A Baltimore County police officer pleaded guilty to misconduct and agreed to resign after admitting to filming himself numerous times engaging in sex acts and neglecting to respond to calls while on duty.

Aaron Z. Pross, 29, who had been assigned to the Pikesville Precinct,took more than 120 images and 20 videos engaging in sexual acts with himself, including one where he masturbated inside his patrol car while reports of "possible guns involved," can be heard over a police radio, prosecutors said.

"He did not respond to calls when he should have," said Baltimore County state's attorney Scott Shellenberger, after Pross' plea hearing.

Prosecutors listed multiple instances when Pross had filmed himself and neglected his duties, including one night where he and an adult woman engaged in sexual acts in front of his patrol car, behind a 7-Eleven in Pikesville, charging documents said. Pross handcuffed her, put her on the hood of the patrol car and took pictures with her phone and sent them to his phone, documents said.

The officer also sent at least one video to a 16-year-old girl, which prompted the investigation in January after the girl's father found images sent to her email.

Pross' attorney Shaun F. Owens said in the court that Pross believed the teen was 22 years old. Owens declined to comment further after Monday's hearing.

Pross, a five-year veteran with Baltimore County, was assigned to an administrative position when the investigation began and his police powers were suspended, the department said.

A31-year-old Baltimore Police officer was charged Friday with pimping out his wife after officers from a human trafficking task force found him outside a hotel room where the woman had agreed to have sex for cash with an undercover officer.

July has seen more than 40 homicides so far, making it the second month in 2015 that homicides in Baltimore city have risen above 40. Homicides are also up across the board since 2014. See our homicide map here for a deeper dive into the data. Data accurate as of July 29, 2015 Months with more...

In 2015, Baltimore has seen two months with more than 40 homicides in a single-year period since the 1970s when the city's population was around 300,000 more residents, or during the 1990s when the number of homicides peaked at 353 murders.